Process of applying a cfrp patch on a steel plate to be formed

Abstract

A process of producing a composite motor vehicle component, the process comprising the steps of: heating a surface treated steel part (1) to an austenite temperature so as to form austenite in said steel part; forming the steel part to a desired shape, cooling the steel part to a temperature below 500 ° C., applying a patch (2) of a prepreg fibre reinforced polymer to at least a part of said steel part, pressing the applied patch (2) of fibre reinforced polymer into adhesion to steel part (1), and at least partly curing said patch inside said pressing tool.

1 . A process of producing a composite motor vehicle component, the process comprising the steps of:
 heating a surface treated steel part ( 1 ) to an austenite temperature so as to form austenite in said steel part;   forming the steel part ( 1 ) to a desired shape,   cooling the steel part ( 1 ) to a temperature below 500° C.,   applying a prepreg fibre reinforced polymer part ( 2 ) to at least a part of said steel part,   pressing the prepreg fibre reinforced polymer part ( 2 ) into adhesion to steel part ( 1 ), and at least partly curing said fibre reinforced polymer part ( 2 ).   
     
     
         2 . The process according to  claim 1 , wherein the step of forming the steel part ( 1 ) to a desired shape is performed inside a forming tool, and wherein the step of applying the prepreg fibre reinforced polymer part ( 2 ) to the steel part ( 1 ) is performed in a pressing tool different from said forming tool. 
     
     
         3 . The process according to  claim 2 , wherein the steel part is transferred from the forming tool to the pressing tool over a transfer line. 
     
     
         4 . The process according to  claim 1 , wherein no surface treatment is performed on the steel part ( 2 ) between the step of forming the steel part and the step of applying the prepreg fibre reinforced polymer part ( 2 ) to at least a part of said steel part. 
     
     
         5 . The process according to  claim 4 , wherein the steel part ( 1 ) and the prepreg fibre reinforced polymer part ( 2 ) are joined without the use of other adhesives than the inherent polymer of the fibre reinforced polymer part ( 2 ). 
     
     
         6 . The process according to  claim 1 , wherein the pressing tool is kept pressed towards the fibre reinforced polymer part ( 2 ) on the steel part ( 1 ) less than 40 seconds, preferably less than 30 seconds. 
     
     
         7 . The process according to  claim 1 , wherein the fibre reinforced polymer part ( 2 ) is attached to a portion of the steel part ( 1 ) that has been deformed during forming thereof, and wherein the fibre reinforced polymer part ( 2 ) is arranged to cover at least apart of said deformed portion of the steel part. 
     
     
         8 . The process according to  claim 1 , wherein the fibre reinforced polymer part ( 2 ) comprises carbon fibres embedded in epoxy. 
     
     
         9 . The process according to  claim 1 , wherein said pressing tool is heated to a temperature above 120° C. during pressing of the fibre reinforced polymer part ( 2 ) to the steel part ( 1 ). 
     
     
         10 . The process according to  claim 1 , wherein the fibre reinforced polymer part ( 2 ) is attached to the steel part ( 1 ) before said steel part ( 1 ) has cooled down and still has a temperature of at least 150° C. when applied to the steel part. 
     
     
         11 . The process according to  claim 1 , wherein the steel part ( 1 ) is produced of a steel that has been treated with an oxide scale inhibiting layer. 
     
     
         12 . The process according to  claim 11 , wherein the steel part ( 1 ) is produced of a steel that has been covered with an Al—Si layer. 
     
     
         13 . The process according to  claim 1 , wherein the steel part ( 1 ) is produced of a steel that has been surface treated so as to form an oxide of a structure to which the fibre reinforced polymer part ( 2 ) may attach, the formed oxide structure comprising a 1.5-4 μm thick scale, formed of iron oxides. 
     
     
         14 . The process according to  claim 1 , wherein the steel part ( 1 ) is produced of a stainless steel. 
     
     
         15 . The process according to  claim 1 , wherein the steel part ( 1 ) is formed of an austenitic steel that forms a martensitic structure by air hardening, and that the process comprises the step of cooling the steel part with the applied fibre reinforced polymer part ( 2 ) without rapid quenching. 
     
     
         16 . A motor vehicle component comprised of a formed steel part ( 1 ) and an applied fibre reinforced polymer part ( 2 ), characterised in that it is been produced by a process according to  claim 1 . 
     
     
         17 . The process according to  claim 2 , wherein no surface treatment is performed on the steel part ( 2 ) between the step of forming the steel part and the step of applying the prepreg fibre reinforced polymer part ( 2 ) to at least a part of said steel part. 
     
     
         18 . The process according to  claim 3 , wherein no surface treatment is performed on the steel part ( 2 ) between the step of forming the steel part and the step of applying the prepreg fibre reinforced polymer part ( 2 ) to at least a part of said steel part. 
     
     
         19 . The process according to  claim 2 , wherein the pressing tool is kept pressed towards the fibre reinforced polymer part ( 2 ) on the steel part ( 1 ) less than 40 seconds, preferably less than 30 seconds. 
     
     
         20 . The process according to  claim 3 , wherein the pressing tool is kept pressed towards the fibre reinforced polymer part ( 2 ) on the steel part ( 1 ) less than 40 seconds, preferably less than 30 seconds.